US3301472A

US3301472A - Blower

Info

Publication number: US3301472A
Application number: US425464A
Authority: US
Inventors: Farris E Dixon; Robert B Duggan
Original assignee: American Radiator and Standard Sanitary Corp
Current assignee: American Radiator and Standard Sanitary Corp
Priority date: 1965-01-14
Filing date: 1965-01-14
Publication date: 1967-01-31
Anticipated expiration: 1984-01-31

Description

' Jan. 31, 1967 F. EJDIXON ETAL BLOWER 2 Sheets-Sheet 1 Filed Jan. 14, 1965 MUN INVENTORS Farris E. Dixon Robert B. Duggon ATTORNEY Jan. 31, 1967 F. E. DIXON ETAL BLOWER Filed Jan. 14, 1965 2 Sheets-Sheet 2 FIG. 3.

ATTORNEY United States Patent l BLOWER Farris E. Dixon and Robert B. Duggan, both of Louisville, Ky., assignors to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Filed Jan. 14, 1965, Ser. No. 425,464 3 Claims. (Cl. 230-127) This invention pertains to blowers and more particularly to blowers for moving air or gases or combinations thereof to particular preselected regions.

Blowers are used to move air and gases to preselected regions in many devices. They are particularly useful in climate control apparatus. In a particular climate control application, blowers are employed to direct a mixture of air and gases to a combustion site where the mixture is burned to generate heat. With respect to heat generating apparatus, there has become available a high heat flux type boiler with a low water content, a large combustion area, and low mass relative to the rate at which fuel is burned. Insuch a boiler the heat exchanger surrounds a particular type burner. The burner includes a cylinder of heat resistant fabrics which because of their large number of combustion sites produce heat with greater efficiency, at higher temperatures and at faster rates. However, such burners require a premixed combination of air and a gaseous hydrocarbon which is fed to the burner under sufliciently high pressureto pass through the fabric. This pressure is relatively high for blowers in which the gases are centrifugally collected in a scroll. Along with the requirement that the delivery of the gaseous mixture be at a relatively high pressure there is the requirement that the delivery be at a relatively low rate. While the two requirements can be satisfied by the use of a high capacity blower whose output is restricted down to provide the :high pressure and low delivery capacity, such a blower is expensive and inefficiently used. Furthermore, such a blower is quite noisy.

It is, therefore, a general object of the invention to provide an improved blower.

It is another object of the invention to provide a blower which has a low delivery rate and a high delivery pres sure, and at the same time is much less expensive than presently available blowers.

It is a further object of the invention to provide an improved blower wheel for a blower which when operating is relatively quiet.

It is yet a further object of the invention to provide an improved scroll for a blower which is simple to fabricate.

Briefly, the invention contemplates a blower which includes a scroll and a blower wheel within the scroll. The scroll comprises oppositely extending arcuate inner and outer peripheral walls. The separation between the walls and the axial lengths of the walls increases along the arcuate direction. First and second end walls abut the peripheral walls with the spacing between the end walls increasing along the :arcuate direction. The blower wheel includes an axle portion and a plurality of blades extending radially from the axle portion. Successive blades of the plurality of blades have different radial lengths.

Other objects, the features and advantages of the invention will be apparent from the following detailed descrip tion when read with the accompanying drawings which show, by way of example and not limitation, the now preferred embodiment of the invention.

In the drawings:

FIG. 1 is an end view of a blower showing the relation between the scroll and blower wheel of the blower in accordance with the invention;

3,391,472 Patented Jan. 31, 1967 FIG. 2 is a side view of the scroll of FIG. 1;

FIG. 3 is a plan view of one embodiment of the blower wheel of FIG. 1; and

FIG. 4 is a side view of the blower wheel of FIG. 1 showing its connection via an axle to a motor.

Referring to FIG. 1, the blower 19 is shown including a scroll 12 and the blower wheel 14 impeller with scroll 12. Scroll 12 is of the centrifugal type including two parts 12A and 123 (FIG. 2). Part 12A, which is of a vacuum molded plastic, includes inner and outer

peripheral walls

16 and 18 and an end wall 20. End wall 20 is integral with

peripheral walls

16 and 18. As is apparent from FIG. 1, the

peripheral walls

16 and 18 are arcuate and preferably have spiral projections. Furthermore, the radial separation between the oppositely disposed

peripheral walls

16 and 18 smoothly and continuously increases along the arcuate direction in the direction of rotation of the blower wheel 14. In addition, as is clearly shown in FIG. 2, the axial width W of the

peripheral walls

16 and 18 smoothly and continuously increases along the arcuate direction toward the outlet 21.

Part 1213 is the second end wall of the scroll and is a flat plate of sheet metal which can incorporate a motor mount and/or structural support. Part 12B is joined to part 12A along the flange portion 22 thereof. Part 1213 is further provided with a central aperture which is both the inlet and provides a passageway for the axle 24 which is connected to blower wheel 14.

Blower wheel 14, which is of galvanized steel or aluminum, will now be described, primarily, with respect to FIGS. 3 and 4.

Blower wheel 14 is an integral structure including an axle or hub portion 26 and a plurality of circumferentially equidistantly spaced vane portions 28 radially extending from axle portion 26. The vane portions 28 generally lie in a plane which is perpendicular to the axis of rotation R. Corrugations 30 are formed in vanes 28-to provide mechanical rigidity thereto. Each of the vanes includes a pair of

blades

32, 34. The

blades

32 and 34 laterally extend from the vane plane and preferably make a right angle therewith. Furthermore, not only are the

blades

32 and 34 perpendicular to the vane plane but lie in diverging planes which are tangent to a circle having its center on the axis of rotation R. As the diameter of the circle approaches zero the diverging planes approach radial planes which include the axis of rotation R. In other words, the blades extend in a mutual diverging relationship from the axle portions 26.

In each blade pair, the radial displacement of the

outer blade tips

36 and 38 is the same radial distance from the axis of rotation R. However, the

inner blade tips

40 and 42 are different radial distances from the axis of rotation R. Therefore, in each blade pair, the length of blade 32, i.e., the distance from the inner blade tip to the outer blade tip is greater than the length of blade 34. In fact, the radial of blade 32 is preferably 1.5 times longer. Furthermore, the angular separation between t-he blade 32 and the blade 34 of one blade pair is less than the angular separation between the blade 32 and the blade 34A of the

adjacent blade pair

34A, 32A. In fact, the angular separation between

blades

34A and 32 is preferably 25 degrees, and the angular separation between

blades

34 and 32 is preferably 20 degrees. Hence, it should be apparent that successive blades are of different length and have different angular separations from their immediate adjacent blades. In addition, the width W of the blades is preferably less than 0.5 times the length of the blade.

Axle 24 is fixed to blower wheel 18 by passing through a central hole thereof and being peened over a washer 44. A central hole in axle 24 accepts the shaft 46 of motor 48. Set screws 50 fix axle 24 to shaft 46.

There has thus been shown an improved blower which quietly moves gases at high pressure and low capacity. In a working embodiment, a blower according to the invention pumps an air-gas mixture at a delivery rate of twenty-five cubic feet per minute with a pressure of 2.8 inches of water. The blower wheel which was driven at 3000 revolutions per minute had a radius of four inches with the longer blades thereof having lengths of about 2.25 inches and widths of about 0. 63 inch.

While only one embodiment of the invention has been shown and described in detail there will now be obvious to those skilled in the art many modifications and variations which satisfy many or all of the objects of the invention. However, these modifications and variations will not depart from the spirit of the invention as defined by the appended claims.

What is claimed is:

1. A blower impeller comprising a central substantially flat disc-like hub portion, an axle member secured to said hub portion centrally thereof and defining the axis of rotation of the impeller, and a plurality of circumferentially equidistantly spaced impeller blades on the hub portion projecting equal distances radially therefrom, each impeller blade being substantially U-sh'aped in cross section and having a frontal substantially flat face lying in a common plane with the frontal faces of the other blades, said plane perpendicular to the axis of rotation of the impeller, each impeller blade also having opposed substantially flat sides which project rearwardly of the frontal face substantially at right angles thereto, the rear edges of said sides of all blades terminating in a common plane parallel to the first-named common plane so that all of said blades are of the same depth axially of the impeller, all of said blades beingof the same circumferential width, said circumferential width being somewhat less than the equal circumferential spacing of the blades, one side of each impeller blade being radially shorter than the opposite side thereof and having its inner end terminating a greater distance radially from the center of the impeller than said opposite side, the radially shorter sides of the blades being adjacent to the radially longer sides of the next blade of the impeller, whereby short and long impeller blade sides are alternately arranged around the circumference of the impeller with a lesser circumferential space between short and long sides of each blade than between short and long sides of adjacent blades.

2. A high pressure low delivery rate blower comprising a blower impeller as defined by claim 1, and a scroll receiving and enclosing said impeller and having an axial inlet and a substantially tangential outlet, said scroll having a substantially circumferential passage substantially surrounding the circumference of the impeller and gradually increasing in width radially from a point on said circumference toward the scroll outlet, the scroll having a flat side normal to the axis of rotation of the impeller and facing the rearward edges of the impeller blade sides and having an oblique side facing said frontal faces of the impeller blades.

3. An impeller fora blower comprising a unitary sheet metal impeller body, said body comprising a central disclike :hub portion adapted for attachment to a driving shaft, and a plurality of circumferentially equidistantly spaced blades on the hub portion projecting equal distances radially therefrom, each blade being substantially U-shaped in cross section and including a frontal fiat face and opposed flat sides arranged perpendicular to said flat face, the frontal faces of all blades lying in a common plane normal to the axis of rotation of theimpel-ler and all of said blade sides radiating from the center of the impeller, one side of each blade being radially shorter than the opposite side thereof and having its inner end positioned "a greater distance radially from the center of the impeller than the corresponding end of said opposite side, the rear edges of all of said blade sides terminating in a common plane parallel to the first-named common plane, the axial depth of said blades being equal and the axial depth being materially less than the circumferential width and the radial length of said blades, the circumferential width of each blade between its sides being less than the circumferential spacing of the blades, the radially .shorter side of each blade lying next to the longer side of the adjacent blade.

References Cited by the Examiner UNITED STATES PATENTS 42,716 5/1864 Rammell 103-115 867,874 10/1907 Capell 230-134 1,083,739 1/1914 Guyer 103-115 1,404,298 1/1922 Jacobs 230-134 1,817,169 8/1931 Schwitzer et al. 230-134 1,868,008 7/1932 Gardner 230- 1,895,488 1/1933 Reisinger 230-127 2,176,325 10/1939 Bretzloff et al. 230-134 2,715,814 8/1955 Barr 230-127 2,976,352 3/1961 Attlla 230-117 3,006,603 10/1961 Caruso et al 230-127 3,145,912 8/1964 Weis 230-127 FOREIGN PATENTS 72,020 5/1943 Czechoslovakia. 462,206 11/1913 France. 165,330 11/1905 Germany.

11,366 1909 Great Britain. 414,593 8/1934 Great Britain. 519,630 4/1940 Great Britain. 941,343 11/1963 Great Britain.

DONLEY .l. STOCKING, Primary Examiner. HENRY F. RADUAZO, Examiner.

Claims

1. A BLOWER IMPELLER COMPRISING A CENTRAL SUBSTANTIALLY FLAT DISC-LIKE HUB PORTION, AN AXLE MEMBER SECURED TO SAID HUB PORTION CENTRALLY THEREOF AND DEFINING THE AXIS OF ROTATION OF THE IMPELLER, AND A PLURALITY OF CIRCUMFERENTIALLY EQUIDISTANTLY SPACED IMPELLER BLADES ON THE HUB PORTION PROJECTING EQUAL DISTANCES RADIALLY THEREFROM, EACH IMPELLER BLADE BEING SUBSTANTIALLY U-SHAPED IN CROSS SECTION AND HAVING A FRONTAL SUBSTANTIALLY FLAT FACE LYING IN A COMMON PLANE WITH THE FRONTAL FACES OF THE OTHER BLADES, SAID PLANE PERPENDICULAR TO THE AXIS OF ROTATION OF THE IMPELLER, EACH IMPELLER BLADE ALSO HAVING OPPOSED SUBSTANTIALLY FLAT SIDES WHICH PROJECT REARWARDLY OF THE FRONTAL FACE SUBSTANTIALLY AT RIGHT ANGLES THERETO, THE REAR EDGES OF SAID SIDES OF ALL BLADES TERMINATING IN A COMMON PLANE PARALLEL TO THE FIRST-NAMED COMMON PLANE SO THAT ALL OF SAID BLADES ARE OF THE SAME DEPTH AXIALLY OF THE IMPELLER, ALL OF SAID BLADES BEING OF THE SAME CIRCUMFERENTIAL WIDTH, SAID CIRCUMFERENTIAL WIDTH BEING SOMEWHAT LESS THAN THE EQUAL CIRCUMFERENTIAL SPACING OF THE BLADES, ONE SIDE OF EACH IMPELLER BLADE BEING RADIALLY SHORTER THAN THE OPPOSITE SIDE THEREOF AND HAVING ITS INNER END TERMINATING A GREATER DISTANCE RADIALLY FROM THE CENTER OF THE IMPELLER THAN SAID OPPOSITE SIDE, THE RADIALLY SHORTER SIDES OF THE BLADES BEING ADJACENT TO THE RADIALLY LONGER SIDES OF THE NEXT BLADE OF THE IMPELLER, WHEREBY SHORT AND LONG IMPELLER BLADE SIDES ARE ALTERNATELY ARRANGED AROUND THE CIRCUMFERENCE OF THE IMPELLER WITH A LESSER CIRCUMFERENTIALLY SPACE BETWEEN SHORT AND LONG SIDES OF EACH BLADE THAN BETWEEN SHORT AND LONG SIDES OF ADJACENT BLADES.